Endangered Iberian Wolves added to College's DNA Bank

What do a wolf, a dog, and a human all have in common? Why genes, of course.

Which helps explain why Portuguese researchers are sending wolf DNA samples to Cornell’s DNA bank for processing and analysis. Not only does the collaboration support critical conservation efforts for a wolf species on the brink of extinction, it also provides important data for scientists mapping the genes that cause diseases in dogs and humans.

The Iberian wolf, Canis lupus signatus, is a subspecies of grey wolf that inhabits the forest and plains of Portugal and Spain. Over the 20th century, habitat destruction and deliberate eradication programs have caused a precipitous decline in its numbers, and today the wolf is highly endangered. Its presence in Portugal is currently estimated at 250-300 animals, and limited geographically to the country’s northern areas – or less than 30% of its original range.

Since 1988, the wolf has been legally protected in Portugal, and Grupo Lobo, a leading science and advocacy organization devoted to the species, has launched a long-term research-based strategy to promote its conservation. According to Dr. Elisabete Pires, a molecular biologist with the Portugese National Institute for Natural Resources (INRB) in Lisbon, and an associate of the Grupo Lobo, a better understanding of the wolves’ genetic structure and diversity helps design more effective conservation campaigns and policy. “The DNA samples that we collect, help us monitor the movements of wolf populations and track the success of habitat conservation efforts,” said Pires. The studies also help wolf conservationists understand important factors in the species’ genetic viability, such as immunity, she noted.

Samples collected from carcasses and fecal material in the wild, and gathered through non-invasive techniques from live animals at the Center for Recuperation of the Iberian Wolf, are then sent on to Cornell’s DNA bank for processing and analysis. Drawing upon the DNA processing technology and analytical expertise at the College, Grupo Lobo hopes to create a genotype and phenotype DNA database for the entire wolf population of Portugal.

Housed at the College of Veterinary Medicine, Cornell’s NIH-funded Medical Genetics Archive was established in 2006 by Dr. Rory Todhunter, an orthopedic small-animal surgeon, to facilitate discovery of the genes that underlie inherited traits and diseases in animals. Although the bank collects species from a variety of purebred animal species, its primary emphasis is on understanding canine disorders, which in turn will shed light on human diseases.

The common link between today’s domesticated dog breeds and the wolf are the semi-feral, or indigenous dogs that are still found in many parts of the world, including Portugal. These dogs have never been purposefully bred for specific characteristics, but have evolved naturally from their wolf ancestors. In fact, it may be possible that these semi-feral dogs still occasionally cross-breed with wolves. Dr. Marta Castelhano, a research associate at the College who manages the DNA Bank, has helped collect over 1,300 DNA samples from indigenous dogs throughout the world. Most of the DNA samples from these indigenous dogs were collected on site by Adam Boyko and Carlos Bustamante’s research group -- collaborators who were at Cornell and are now at Stanford University. “It’s fascinating to look at mutations that cause diseases in breed dogs,” said Castelhano. “Was a particular mutation created when the breed was established, or was it already present in the breed’s indigenous ancestors?” According to Castelhano, this information may illustrate the genetic basis for certain breed-associated disorders, and eventually help develop new treatments. The strong collaboration between Cornell College of Veterinary Medicine and the geneticists at Stanford now continues through funding from the National Science Foundation.

The wolf and feral dog samples provided by the Portuguese team will allow investigators to compare the genetic makeup of Portuguese semi-feral dogs with that of their Iberian wolf ancestors, shedding additional light on canine domestication and disease mapping. Meanwhile, Cornell’s processing and analysis will also allow the Portuguese team to detect any ongoing cross-breeding between wolves and dogs, as well as to further explore the implications of the status of feral dog populations on wolf survival. “This truly represents a golden opportunity for both groups,” said Castelhano.